SMTP Test Tool – FAQ

Q: What’s going on here?

A: This is a web-based SMTP test tool. If you’re familiar with SMTP servers and how they work, you know that you can manually telnet into the SMTP server and issue commands like HELO and MAIL-FROM and RCPT-TO to send a test email or just see how the SMTP server responds to commands. This web-based tool makes it so you can run diagnostic sessions on SMTP servers over the web, rather than having to use telnet and issue manual commands, which can be cumbersome.

Q: Why would I need to use this?

A: If you’re having difficulty getting emails delivered by your SMTP server, it might not be readily apparent what the issue is, and you might find yourself writing test code to figure it out. With this tool, you can easily see what’s going wrong with an SMTP server. Perhaps your login credentials are failing. Perhaps the SMTP server has run out of disk space. Perhaps the SMTP account is throttling you because of pre-established sending limits. By looking at the exact SMTP server responses, you can easily troubleshoot an issue.

Q: How is this SMTP Test Tool related to GMass? If I’m a GMass user, do I need to test my SMTP server here?

A: This SMTP Test Tool was created by GMass, and can be used by GMass users, but it’s really for everyone, including non-GMass users. If you’re a GMass user and you’re using the unlimited email sending option by connecting your account to an SMTP server, and you’ve having difficulty connecting your SMTP account, this tool will help you troubleshoot. Even if you’re not a GMass user but are using an SMTP server and having difficulty, this tool will help you troubleshoot.

Q: I’ve found other SMTP testing tools on the web. What makes this one so special?

A: I believe I’ve created the world’s best web-based SMTP testing tool, because with my tool, you can:

Authenticate by IP or Username/Password.

Specify a port other than 25.

Choose from multiple security options, including SSL, TLS, and STARTTLS.

See the SMTP conversation happen live before your eyes, shown in an easy-to-read color-coded format.

Q: I’m specifying a Username and Password, but I noticed that in the SMTP session, the Username and Password look a lot different from how I’m entering them.

A: That’s because we base-64 encode your Username and Password before passing it into the SMTP server for validation. That’s part of the SMTP standard.

Q: The SMTP server I’m testing authenticates by IP address instead of Username/Password. How can I run a diagnostics session?

A: Leave the Username/Password fields blank, and set your SMTP server to accept connections from this IP address: 52.35.85.201. That is the IP address used for outbound connections to the SMTP server that you specify.

Q: If I enter my SMTP Username and Password, is it safe?

A: Yes, it’s pretty safe. We don’t store any of the information entered to test an SMTP server. It simply passes through ephemerally to conduct the SMTP connection test, and then the information disappears from our server.

Q: What happens if my test is successful?

A: A successful test will result in a one-line email message being sent from the email address specified to the email address specified. To protect against this tool being used to send spam, the “test message” cannot be modified.

Error- ERROR: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 50.63.202.1:25

Campaign-level Error Description:
Unable to connect to the SMTP server set for your account, mail.XXXXXXXXXXXX.XX. No connection could be made because the target machine actively refused it 162.214.3.101:26

Hi GMass,
Thanks for the SMTP test tool.
Please consider adding an actual message to be sent along as the message body. It can be as simple as “This is a test message.” It seems according to the SMTP RFC, a completely blank message body is not allowed and some servers honor this requirement strictly (https://tools.ietf.org/html/rfc2045#section-5.1)

Hi and thank you for the help.
I would like to use the smtp function to send 500 to 1k email messages. I am a member of Sendgrid. I’ve tried to use the SMTP tool for some to to no success. I’ve used api then the api id for password. No luck. Tried using my sendgrid user/password no success. Results always invalid username/password. No matter what password I use, either api key; A27UU64MQOuvUhj1lB9ZaQ or the encrypted dots. Login: